Respiration Flashcards
What do all cells need to carry out life processes?
Energy. Provided for by ATP
What is cell respiration?
The process of breaking down food molecules to release ATP
Where does cell respiration happen continuously?
Every cell
What are some examples of uses of energy?
Cell division
Contraction of muscle cells
Maintaining body temperature
Transporting molecules
What does aerobic respiration use oxygen to do?
Break down glucose and release energy. Some energy released as heat but most is trapped in a useable form of ATP
Balanced chemical equation for aerobic respiration
C6H12O6 + 6O2 -> 6CO2 + 6H2O
Word equation for aerobic respiration
Glucose + oxygen -> Carbon dioxide + water
What is respiration?
A series of chemical reactions each catalysed by a different enzyme
What is anaerobic respiration?
Respiration without oxygen
Why does aerobic respiration release a lot of ATP?
Because it completely oxidises the glucose
Why does anaerobic respiration release less ATP?
Because the glucose is not completely broken down
What toxic waste does anaerobic respiration produce?
Lactic acid and ethanol
What is the word equation for anaerobic respiration in fungi and plants?
Glucose -> ethanol and carbon dioxide
How is anaerobic respiration useful in food production?
Yeast, single celled fungus in bread and alcohol production. The carbon dioxide produced forms bubbles causing bread to rise. Ethanol produced provides alcohol content in beer and wine.
What is the word equation for anaerobic respiration in plants and fungus?
Glucose -> lactic acid
When does anaerobic respiration occur?
When there is a shortage of oxygen e.g during intensive exercise
What happens to muscle cells during anaerobic respiration?
The glycogen stored is broken down into glucose providing additional energy supply
Where is lactic acid transported to?
The liver where it is oxidised
Why do we keep breathing heavily after exercise?
To supply the extra oxygen needed to dispose of the lactic acid.
What is oxygen debt?
The volume of oxygen needed to oxidise lactic acid
What do we want to show when investigating respiration?
Only living things respire
What is a control experiment?
Identical to the original without the independent variable which we think will affect results
Name a classic experiment to demonstrate respiration
Germinating peas
Describe germinating peas experiment
Growing peas respire and release heat
Place one set of germinating keys in a thermos and another set of dead peas in another thermos
Both sets of peas have been soaked in Milton solution to kill bacteria
Both thermos’ are plugged with cotton wool
Each thermos has a thermometer passing through the cotton wool into the peas
Temperature rise will demonstrate respiration as respiration releases heat
What additional test for respiration can be used in germinating peas experiment?
Carbon dioxide test for limewater
Describe hydrogen carbonate indicator and insects experiment
Two tubes containing hydrogen carbonate indicator
Airtight due to fitting bung
One tube contains an insect, the other is empty
Hydrogen carbonate indicator turns from red to yellow when carbon dioxide concentration increases
Describe an experiment to investigate anaerobic respiration in yeast
Place some glucose and yeast in a suspension in a boiling tube with a thin layer of oil on top
Place delivery tube in a bung passing to another test tube containing limewater
